Connect to PostgreSQL Data from Blazor Apps

Blazor is a framework for developing modern, client-side web UIs using .NET technology. Instead of coding in JavaScript, developers can use the familiar C# language and .NET libraries to build app UIs.

The CData ADO.NET Provider for PostgreSQL can be used with standard ADO.NET interfaces, such as LINQ and Entity Framework, to interact with live PostgreSQL data. Since Blazor supports .NET Core, developers can use CData ADO.NET Providers in Blazor apps. In this article, we will guide you to build a simple Blazor app that talks to PostgreSQL using standard SQL queries.

Install the CData ADO.NET Provider for PostgreSQL

CData ADO.NET Providers allow users to access PostgreSQL just like they would access SQL Server, using simple SQL queries.

Install the PostgreSQL ADO.NET Data Provider from the CData website or from NuGet. Search NuGet for "PostgreSQL ADO.NET Data Provider."

Create a PostgreSQL-Connected Blazor App

Start by creating a Blazor project that references the CData ADO.NET Provider for PostgreSQL

1. Create a Blazor project on Visual Studio.
👁 Create a Blazor app project.

2. From the Solution Explorer, right click Dependencies, then click Add Project Reference.
3. In the Reference Manager, click the Browse button, and choose the .dll file of the installed ADO.NET Provider (e.g. System.Data.CData.PostgreSQL.dll, typically located at C:\Program Files\CData\CData ADO.NET Provider for PostgreSQL\lib etstandard2.0).
👁 Reference ADO.NET for PostgreSQL .dll in the Blazor app.

SELECT PostgreSQL Data from the Blazor App

1. Open the Index.razor file from the Project page.
2. In a PostgreSQLConnection object, set the connection string:

   To connect to PostgreSQL, set the Server, Port (the default port is 5432), and Database connection properties and set the User and Password you wish to use to authenticate to the server. If the Database property is not specified, the data provider connects to the user's default database.

   SSH Connectivity for PostgreSQL

   You can use SSH (Secure Shell) to authenticate with PostgreSQL, whether the instance is hosted on-premises or in supported cloud environments. SSH authentication ensures that access is encrypted (as compared to direct network connections).

   SSH Connections to PostgreSQL in Password Auth Mode

   To connect to PostgreSQL via SSH in Password Auth mode, set the following connection properties:

   • User: PostgreSQL User name
   • Password: PostgreSQL Password
   • Database: PostgreSQL database name
   • Server: PostgreSQL Server name
   • Port: PostgreSQL port number like 3306
   • UserSSH: "true"
   • SSHAuthMode: "Password"
   • SSHPort: SSH Port number
   • SSHServer: SSH Server name
   • SSHUser: SSH User name
   • SSHPassword: SSH Password

   SSH Connections to PostgreSQL in Public Key Auth Mode

   To connect to PostgreSQL via SSH in Password Auth mode, set the following connection properties:

   • User: PostgreSQL User name
   • Password: PostgreSQL Password
   • Database: PostgreSQL database name
   • Server: PostgreSQL Server name
   • Port: PostgreSQL port number like 3306
   • UserSSH: "true"
   • SSHAuthMode: "Public_Key"
   • SSHPort: SSH Port number
   • SSHServer: SSH Server name
   • SSHUser: SSH User name
   • SSHClientCret: the path for the public key certificate file

   For example: User=postgres;Password=admin;Database=postgres;Server=127.0.0.1;Port=5432;

3. The code below creates a simple Blazor app for displaying PostgreSQL data, using standard SQL to query PostgreSQL just like SQL Server.

    @page "/"
    @using System.Data;
    @using System.Data.CData.PostgreSQL;
    
    <h1>Hello, world!</h1>
    
    Welcome to your Data app.
    
    <div class="row">
    <div class="col-12">
    
    @using (PostgreSQLConnection connection = new PostgreSQLConnection(
    "User=postgres;Password=admin;Database=postgres;Server=127.0.0.1;Port=5432;"))
    {
    var sql = "SELECT ShipName, ShipCity FROM Orders";
    var results = new DataTable();
    
    PostgreSQLDataAdapter dataAdapter = new PostgreSQLDataAdapter(sql, connection);
    dataAdapter.Fill(results);
    
    <table class="table table-bordered">
    <thead class="thead-light">
    <tr>
    @foreach (DataColumn item in results.Rows[0].Table.Columns)
    {
    <th scope="col">@item.ColumnName</th>
    }
    </tr>
    </thead>
    <tbody>
    @foreach (DataRow row in results.Rows)
    {
    <tr>
    @foreach (var column in row.ItemArray)
    {
    <td>@column.ToString()</td>
    }
    </tr>
    }
    </tbody>
    </table>
    }
    </div>
    </div>
    

4. Rebuild and run the project. The ADO.NET Provider renders PostgreSQL data as an HTML table in the Blazor app. 👁 Query PostgreSQL from Blazor app.
   

   At this point, you have a PostgreSQL-connected Blazor app, capable of working with live PostgreSQL data just like you would work with a SQL Server instance. Download a free, 30-day trial and start working with live PostgreSQL data in your Blazor apps today.